Not Applicable
Not Applicable
The present invention relates to wafer fabrication systems used in the manufacture of integrated circuit devices and more specifically to a modular and configurable front end, buffer or frame employed within such systems.
Wafer fabrication systems are known that include a frame and a number of loaders or pod door openers (PDOs) within the system that are used for loading and unloading wafers for processing. A wafer fabrication system typically includes an input port for receiving wafers via a wafer cassette that may be mounted within a loader, a transport mechanism or robot for manipulating and moving a wafer to a processing station and a processing station for performing a desired fabrication process such as ion implantation, photolithography and metrology. Known wafer fabrication systems include a frame that is assembled based upon the specific number of loaders to be employed within the particular wafer processing system. The frame typically comprises a skeleton that includes steel frame members or components that are welded together to form the frame assembly.
Wafer fabrication system frames produced in the above manner have a number of drawbacks. First, large numbers of component parts need to be inventoried or produced to accommodate the different frame sizes. Second, welding of the frames is a time consuming labor intensive process and is inherently prone to large machine tolerances. Third, the lead time to produce a wafer fabrication system frame that employs numerous components is fairly great given the labor involved. Fourth, storage and transportion of welded frames is costly due to their large volumes. Additionally, there may be lead times associated with the fabrication of specific components of the frame if it is not designed to inventory all possible components.
For the above reason it would be desirable to be able to construct a frame for the front end of a wafer fabrication system that employs a small number of components. Such a frame should accommodate commercially available loaders, provide accurate registration among the component parts of the frame, be cost efficient to manufacture, and be assembled to accomodate one or more loaders.
In accordance with the invention a modular frame for a configurable front end for a wafer fabrication system is disclosed. The configurable frame includes one or more predetermined base castings and one or more predetermined upstanding pod door opening (PDO) castings adapted to mate with corresponding base castings. Via use of the base and PDO castings, frames may be readily assembled from standard components without necessitating weldments or custom manufacture of components to accommodate a desired a number of loaders.
More specifically, in a preferred embodiment a modular frame is constructed from one or more self-referencing aluminum base castings and one or more upright self-referencing aluminum PDO castings.
The modular nature of the castings permit multiple configurations of wafer fabrication system frames to be constructed out of a limited number of base and PDO castings.
Other features, aspects and advantages of the invention will be apparent to those of ordinary skill in the art from the detailed description of the invention that follows.